When your Briggs and Stratton lawn mower isn’t running as smoothly as it should, the governor might be the culprit. This small device controls the engine’s speed, ensuring it operates within a safe range. Adjusting the governor is a straightforward process, but it requires precision.
This guide will walk you through the steps to adjust the governor on your Briggs and Stratton lawn mower, helping your engine run efficiently.
How to Adjust Governor on Briggs and Stratton
Tools You Will Need
- Socket wrench set
- Pliers
- Screwdriver
- Safety gloves
- Torque wrench (optional but recommended)
These basic tools are enough to complete the job, and using the right tools will make the process faster and safer.
1. Turn Off the Engine and Disconnect the Spark Plug
Safety comes first. Before you start any work on your mower, ensure the engine is turned off and cool. Disconnect the spark plug to prevent any accidental starting during the adjustment process. This is a vital safety precaution, as the engine can suddenly engage if the plug is connected.
2. Locate the Governor Arm and Linkage
The governor’s arm is typically mounted on the side of the engine block, connected to the throttle and carburetor via a linkage. On a Briggs and Stratton engine, the governor is often easy to spot near the carburetor and air filter assembly.
- Look for a small lever or arm connected to the throttle shaft.
- You’ll also notice a spring and a linkage that connects the governor to the throttle.
Once located, you’ll be ready to start adjusting.
3. Loosen the Governor Arm Nut
Using a socket wrench, slightly loosen the governor arm nut. This nut holds the governor lever on the shaft protruding from the engine. You don’t need to remove the nut entirely, just loosen it enough to move the arm freely.
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4. Adjust the Governor Shaft
Now, with the governor arm loose, grab the governor shaft using a pair of pliers. Turn the shaft in the same direction as it would rotate under normal engine operation. Usually, this means rotating it counterclockwise on a Briggs and Stratton engine.
Note: Refer to your engine’s manual to confirm the correct direction if unsure, as rotating the governor shaft the wrong way can cause incorrect adjustment.While holding the shaft in this position, move the governor arm to its wide-open throttle position. This action synchronizes the governor with the throttle mechanism.
5. Tighten the Governor Arm Nut
With the governor shaft held in the proper position and the governor arm in the wide-open throttle position, retighten the governor arm nut. Use a socket wrench to secure the nut snugly but avoid overtightening, which can damage the governor components.
6. Check the Governor Spring
Once the governor’s arm is properly aligned, check the tension on the governor’s spring. This spring helps the governor regulate engine speed by pulling the throttle open or closed in response to engine load. Over time, the spring may stretch or wear out, affecting its performance.
- Ensure the spring has enough tension to pull the throttle open when needed but isn’t overstretched.
- Replace the spring if it looks worn or if you suspect it’s causing speed regulation issues.
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7. Reconnect the Spark Plug and Test the Engine
With the governor adjusted, reconnect the spark plug wire and start the mower’s engine. Let the engine run and observe its behavior. You should notice a smoother, more consistent idle and better throttle response.
If the engine still surges or idles incorrectly, the governor may need further fine-tuning, or there could be another underlying issue with the carburetor or throttle linkage.
8. Fine-tune the Governor (If Necessary)
If the initial adjustment didn’t completely resolve the issue, you might need to fine-tune the governor.
Repeat the adjustment process, this time making small, incremental changes to the governor arm position until the engine runs smoothly at all throttle levels.
Check the engine’s performance at both idle and full throttle to ensure the governor is correctly managing speed variations. At full throttle, the engine should reach its designed RPM without overrevving or bogging down.
Signs That Your Governor Needs Adjustment
You may need to adjust your Briggs and Stratton mower’s governor if you notice the following issues:
- The engine is running at irregular speeds.
- The mower stalls or surges while mowing.
- The engine idles too fast or too slow.
- The mower doesn’t reach full speed when throttled up.
These symptoms typically indicate that the governor is either not regulating the engine speed correctly or is out of sync with the throttle.
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Common Mistakes to Avoid When Adjusting the Governor
- Overtightening the governor arm nut: This can damage the governor’s mechanism or restrict its movement.
- Turning the governor shaft in the wrong direction: Always check the engine’s manual to ensure you rotate the shaft in the correct direction, as turning it the wrong way can throw off the governor’s settings.
- Neglecting spring tension: A worn or improperly tensioned spring can cause erratic engine speeds even after adjusting the governor arm.
- Skipping the test run: Always test the mower after making adjustments to confirm the governor is working correctly.
When to Consider a Governor Replacement
In some cases, adjusting the governor might not solve the issue, especially if the governor components are worn or damaged. If you notice that the governor arm is loose, the linkage is bent, or the spring is overstretched, it may be time to replace the governor.
Replacing the governor is a more involved task that may require disassembling part of the engine, so if you’re not comfortable with this level of repair, consider taking your mower to a professional.
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How to Maintain Briggs and Stratton Lawn Mower Governor
- Regularly check the governor linkage: Over time, the governor linkage can become loose or misaligned, especially if the mower is used frequently on rough terrain.
- Clean the carburetor: Dirt and debris in the carburetor can affect the governor’s ability to regulate engine speed, so keep it clean.
- Inspect the governor spring: A weak or worn governor spring can cause the same symptoms as a misadjusted governor. Replace it as needed.
- Monitor engine performance: If the engine starts to exhibit signs of erratic speed or stalling, check the governor settings before assuming it’s a more serious engine issue.
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FAQ
How do you adjust the governor on a Briggs and Stratton engine?
- Turn off the engine and disconnect the spark plug for safety.
- Locate the governor arm and linkage, typically on the side of the engine, near the carburetor.
- Loosen the governor arm nut using a socket wrench, but don’t remove it.
- Hold the governor shaft with pliers and rotate it in the same direction it naturally turns when the engine runs (counterclockwise for most Briggs and Stratton engines).
- Move the governor arm to the wide-open throttle position while holding the shaft in place.
- Tighten the governor arm nut after aligning it with the throttle.
- Reconnect the spark plug and test the engine. If needed, fine-tune the governor by repeating the process with small adjustments.
What position should the speed control be when adjusting the governor?
When adjusting the governor, the speed control (throttle) should be in the wide-open throttle (WOT) position. This position ensures that the governor arm and the throttle are aligned correctly during adjustment, allowing the governor to properly regulate the engine’s speed across different loads.
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How do you adjust governor sensitivity?
Governor sensitivity refers to how quickly the governor responds to changes in engine load. To adjust it:
- Locate the governor spring: This is the part responsible for controlling sensitivity. It’s usually connected to the throttle and governor linkage.
- Tighten or loosen the spring:
- Tighten the spring to make the governor more sensitive, which causes the engine to react more quickly to load changes.
- Loosen the spring to reduce sensitivity, causing slower reactions to load changes.
Note that over-adjusting sensitivity can cause the engine to surge or operate erratically, so make small adjustments and test the engine’s response under load.
How to set a governor?
Setting a governor on a small engine involves aligning it correctly with the throttle. Here’s how to set a governor:
- Turn off the engine and disconnect the spark plug for safety.
- Locate the governor arm and shaft on the engine.
- Loosen the governor arm nut so the arm can move freely.
- Hold the governor shaft with pliers and rotate it in the direction it naturally moves.
- Move the throttle to the wide-open position while holding the governor shaft in place.
- Tighten the governor’s arm nut to secure the governor in position.
- Reconnect the spark plug and test the engine to ensure proper speed regulation.
This process aligns the governor with the throttle to regulate the engine speed effectively.
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What are the symptoms of a bad engine governor?
A malfunctioning engine governor can lead to several noticeable symptoms, including:
- Surging or fluctuating engine speeds: The engine speed may rise and fall unpredictably as the governor struggles to maintain a consistent speed.
- Engine stalling under load: If the governor isn’t opening the throttle as needed, the engine might stall when you encounter thick grass or heavy loads.
- Engine runs too fast or too slow: A bad governor may cause the engine to over-rev, potentially leading to damage, or it may idle too slowly, reducing performance.
- Difficulty maintaining idle speed: If the governor is out of adjustment, the engine may have trouble staying at a steady idle speed.
- Unresponsive throttle: A malfunctioning governor may not allow the throttle to respond properly to increases or decreases in engine load.
How does the governor on a lawn mower work?
The governor on a lawn mower works by automatically adjusting the throttle to maintain a consistent engine speed, even as the load changes. This mechanism uses a system of springs and linkages to detect changes in engine load:
- When the load increases (like mowing through thick grass), the engine speed decreases. The governor detects this drop and opens the throttle to increase fuel and air flow, thus bringing the engine back to its optimal speed.
- When the load decreases (e.g., mowing over a light patch), the governor closes the throttle to prevent the engine from over-revving, maintaining a steady speed.
There are two main types of governors in lawn mower engines: mechanical governors, which use centrifugal force from rotating weights to adjust throttle position, and pneumatic governors, which use air pressure from the flywheel to control speed.
In both types, the governor ensures the engine runs efficiently without the operator needing to manually adjust the throttle for different mowing conditions.
Final Word
Adjusting the governor on a Briggs and Stratton lawn mower is a critical maintenance task that ensures your engine runs smoothly and efficiently. With a few basic tools and careful attention to detail, you can adjust the governor yourself, saving money and keeping your mower in top shape.
Note: For more complex repairs or if the governor adjustment doesn’t resolve the problem, consult a professional technician or refer to the Briggs and Stratton service manual for your specific engine model.
